Posted on June 26, 2014

Cape Town, South Africa – Today, at the 92nd General Session & Exhibition of the International Association for Dental Research (IADR), held in conjunction with the IADR Africa/Middle East Regional Meeting, M. Kebschull, Columbia University, New York, N.Y., USA, will present a study titled “Gingival Tissue Transcriptomes Identify Phenotypically Distinct Classes of Periodontitis.”

Currently, the recognized principal forms of periodontitis, chronic (CP) and aggressive (AgP) lack an unequivocal, pathobiology-based foundation. In this study researchers explored whether gingival tissue transcriptomes can serve as the basis for an alternative classification of periodontitis. To do this, the researchers used whole-genome gene expression data from 241 gingival tissue biopsies obtained from sites with periodontal pathology, in 120 systemically healthy non-smokers with periodontitis, with available data on clinical periodontal status, subgingival microbial profiles and serum IgG antibodies to periodontal microbiota.

Adjusted model-based clustering of transcriptomic data using finite mixtures generated two distinct clusters of patients that did not align with the current classification of CP and AgP. Distinct expression profiles primarily related to cell proliferation in Cluster #1 and to lymphocyte activation and unfolded protein responses in Cluster #2. Patients in the two clusters did not differ with respect to age, but presented with distinct phenotypes (statistically significantly different whole-mouth clinical measures of extent and severity, subgingival microbial burden by several species, and selected serum antibody responses). Patients in Cluster #2 showed more extensive/severe disease, and were more often male.

These findings suggest that distinct gene expression signatures in pathological gingival tissues translate into phenotypic differences and can provide a basis for a novel classification.

This research was supported by the National Institutes of Health, Bethesda, Md., USA, grants DE-015649, DE-021820 and UL1-TR000040, and Colgate-Palmolive, N.J., USA.

This is a summary of abstract #169, “Gingival Tissue Transcriptomes Identify Phenotypically Distinct Classes of Periodontitis,” to be presented by M. Kebschull on Thursday, June 26, 2014, 8 a.m. - 9:30 a.m. in Ballroom East of the Cape Town International Convention Centre.